One of the more interesting projects to hit Indiegogo of late is Dimple, an adhesive strip that.
However, as a clever reader named Lukasz pointed out, there's already an app that accomplishes much the same thing. It's called QuickClick, and it allows you to program your Android device's volume buttons for various other tasks, much in the way that the Dimple app will do with those add-on buttons.
It's free, fairly easy to use, and surprisingly effective. Here's how to get started. (Note that my testing was done on a Motorola Moto X. Your mileage -- and compatibility -- may vary.)
Step one: Start QuickClick, then tap "Create a new action."
Step two: Choose from the available functions, which include Flashlight, Photo, Call, and Message. For purposes of our tutorial, tap App, then choose an app you want to be able to quick-launch.
Step three: Now decide what sequence of volume-button presses you want to use for this shortcut. You could use up-down-up, for example, or down-down-down. Make your selection via the onscreen buttons, or use the actual volume buttons. When you're done, tap Ready.
Step four: Review the available settings for this action and make any changes you want. If, for example, you don't want your device to vibrate when the action engages, clear that checkbox. When you're done, tap Finish.
And that's it! Now test the configuration to make sure it works. Wash, rinse, and repeat if you want to create other actions.
Although it may seem odd to hijack your volume buttons this way, QuickClick offers a number of useful settings that can help smooth out the bumps.
For example, by default, the app will restore the previously set volume after it runs your action. So even if you, say, press volume-down four times in a row, the volume will return to its previous level afterward.
You can also choose whether to run the app while music is playing (by default, it does) and when it "listens" for button-presses. For example, perhaps you want it to work only when the screen is off.
Another handy tweak is modifying the interval between clicks (of the buttons). By default, if you wait more than a full second in between, it cancels the QuickClick action. So you could effectively bypass it, adjusting volume as you normally would, by waiting at least a second between presses.
This is a really cool way to mod your Android phone or tablet, something iDevice users only wish they could do. (Count me among them.) QuickClick is free, though if you want the Premium (ad-free) version, it'll cost you just $3.32.